N-(beta-hydroxyethyl)-3,4,5-trihydroxybenzoic acid amide



Patented Oct. 16, 1951 UNITED STATES PATENT OFFICE N- ,B-HYDROXYETHYL)3,4,5-TRIHY- DROXYBENZOIC ACID AMIDE Margaret Rose Zentner, Newark, N.J., and Gerhard Julius Haas, New York, N. Y., assignors to Hofimann-LaRoche Inc., Roche Park, Nutley, N. J a corporation of New Jersey NoDrawing. Application January 31, 1950, Serial No. 141,582

1Claim. (Cl. 260-559) 2 This invention relates to N-(fl-hydroxyethyl)utes, the solution was filtered and concentrated to3,4,5-trihydroxybenzoic acid amide, which maybe 310 cc. in vacuo. Uponcooling the concentrate also designated as N-(fi-hydroxy t y -gallicacid and allowing it to stand for 16 hours at about 4 amide, and to themethod of preparing the same. 0., crystals of N-(fi-hydroxyethyl)-3,4,5-trihy- The new compound is useful in pharmaceutical 5droxybenzoic acid amide, M. P. 217.5218.8 C.,

preparations and more particularly for solubilizwere obtained. Theproduct was recrystallized ing riboflavin. It can also be employed as aninonce by dissolving the crystals in boiling water termediate for thepreparation of other comand cooling the resulting solution. Upon furtherpounds. In general, the N-(B-hydroxyethyl) purification by refluxing therecrystallized mate- 3,4,5-trihydroxybenzoic acid amide can be prerialfor one hour with acetone so as to remove pared by reacting a loweralkyl ester of gallic acid, acetone soluble impurities, there wasobtained as, for example, the methyl ester of gallic acidN-(p-hydroxyethyl)-3,4,5-trihydroxybenzoic acid with monoethanolamine,the latter reagent amide, M. P. 219-220.5 0.

preferably being employed in excess. We claim:

The following example will serve to illustrate N (phydroxyethyl)-3,4,5-trihydroxybenzoic the method of preparing the newcompound. acid amide.

MARGARET ROSE ZENTNER. Example GERHARD JULIUS HAAS.

50 grams of methyl gallate and 40.8 grams of monoethanolamine wereheated together at REFERENCES CITED 115-120 C. for 8 hours. The solidprod t which The following references are of record in the formed wasdissolved in 1,300 cc. of boiling watzeg' file of this patent: V and thesolution was adjusted to pH 3-5 with cc. of 36% hydrochloric acid. 2.5grams of acti- UNITED STATES PATENTS vated charcoal were added and aftermaintaining Number Name Date the temperature at the boiling point for 10min- 2,463,461 Hofier Mar. 1, 1949

